METHOD OF PRODUCING BIMETAL STRING Russian patent published in 2016 - IPC E21B17/01 B23K31/02 B32B1/08 B21C37/06 

FIELD: metallurgy.

SUBSTANCE: invention relates to a method for producing bimetallic tubing and can be used in production of pipe product or repair of tubing. Method includes cleaning of outer and inner surface of tubing from deposits and dirt made of carbon steel, low alloy steel or stainless steel thin-walled electric-welded pipes, drawing on its outer surface, adhesive sealant, introduction of tubing channel wall electrically welded pipes coated with glue . Method then includes performing combined deformation by distributing tubing and said electric-welded pipes, threading, quality control of resulting pipe and hydraulic pressure test. Thin-wall electric-welded tube is made of steel with content of sulphur and phosphorus impurities of more than 0.01 %. During combined deformation of tubing and electric-distribution pipe by providing an increase in diameter of electric welding pipes more than 18 % of original outside of its diameter.

EFFECT: technical result is to improve ductility and formability cold liner without breaking continuity of base metal and welded joints.

1 cl, 2 ex